Prognosis and mitigation strategy for major landslide-prone areas Varunavat Parvat landslide in Uttarkashi

Waste management
Clear-cut policy should be formulated for the waste management of hill slopes
particularly for the planned disposal of debris material generated from the slope cutting
or digging for construction activity. As the slope cut debris not only blocks the natural
drains butevengives rise tonewslide zones anddamages agriculture andforestresources
of the immediate down slope area. Separate funds for planned disposal of road cut debris
should be allocated to the agencies (such as Public Works Department) involved in the
road construction work. Furthermore, the expenditure to be incurred by the concerned
department for the disposal of slope cut/ road cut debris should be proposed in the project
estimate itself. This measure can substantially reduce the risk of landslides and
subsidence to the immediate upslope and down slope areas of newly constructed hill
roads and can also minimize the annual maintenance cost of hill roads.
Avoidance of ground-water harvesting structures in the old slide zones
Recharge wells and ground-water harvesting structures should be avoided in the
upslope areas of old and active slide zones wherein habitations or critical facilities are
located (over old slide zones).
Rainfall database creation
Detailed database for rainfall needs to be created in an attempt to workout the
threshold amount of rainfall that might cause slide or debris flow in the near future.
For this purpose there is an urgent need to increase the number of rain gaze stations in
hill districts.
Landslide risk mapping at municipality ward and village level
Landslide hazard zoning at municipality ward and village Level on 1:4000 and larger
scale should be carried out through conjunctive use of high resolution satellite image of
IKONOS, QUICKBIRD, CARTOSAT 1 and CARTOSAT 2 satellites and precision
ground surveys using Total Station. Furthermore, the GIS techniques can be best
utilized for vulnerability assessment by overlaying the thematic layers of population,
infrastructure, assets and natural resources over the landslide hazard zone maps of the
area. Risk maps at municipality ward and village Level should be created by relating
the landslide hazard potential and vulnerability of the area. Risk maps can provide
information about the likelihood, dimension, extent and degree to which the
communities in the area may be affected by landslides.
References
Agarwal, N.C. and Kumar, G. (1973), “Geology of the upper Bhagirathi and Yamuna valleys,
Uttarkashi district, Garhwal Himalaya”, Himalayan Geology, Vol. 3, pp. 2-23.
Census of India 2001 (2004), Census of India 2001, Office of Registrar-General, New Delhi.
Central Technical Team (2003), “Interim report on Varunavat landslide, Uttarkashi
(Uttaranchal)”, unpublished technical report, Central Technical Team, Governement of
India, New Delhi.
DMMC (2003), “Final report on landslide affected Gyansu and Tambakhari area of Uttarkashi”,
Technical Report No. DMMCUttarkashi:2003:1-570, unpublished tech. report of Disaster
Mitigation and Management Centre, Dehradun.
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